Firstly, an old one based around Jared's observations of user experience on big, well-established brand sites.
...eBay's direct-experience branding works better than Ford's indirect-message branding at giving users a positive opinion of the brand. Therefore, we believe that usability is essential for effective branding. It appears that any obstacles users face will directly (and negatively) affect how they perceive the brand.Branding and Usability by Jared Spool
A second, more recent article giving an overview of his research on a range of e-commerce competitors. Jared observes that when people are done shopping on certain e-commerce sites, their perceptions of the brand are often strengthened, while other sites seem to consistently weaken their brands.
...when we create designs that focus on ensuring users accomplish their goals, we are likely having a long-term positive effect on the strength of the brand.Determining How Design Affects Branding by Jared Spool